62 results about "Spurious response" patented technology

An acoustic wave device having an improved frequency-temperature characteristic and in which a spurious response of the higher order mode is suppressed includes a piezoelectric substrate made of LiNbO₃, a SiO₂ layer laminated on the piezoelectric substrate, and an IDT electrode disposed in an interface of the piezoelectric substrate and the SiO₂ layer, wherein φ and θ of Euler angles expressed by (φ, θ, ψ) of LiNbO₃ substrate satisfy φ=0° and 80°≦θ≦130°, respectively. The acoustic wave device using an acoustic wave primarily having an SH wave, wherein ψ is set to satisfy 5°≦ψ≦30°.

Apparatus and methods for distributing spurious tones through the frequency domain are disclosed. One such apparatus can include a dithering circuit configured to generate a sequence of numbers that exhibit statistical randomness and a variable frequency circuit configured to adjust a frequency of an output based on the sequence of numbers so as to spread energy of spurious tones in a frequency response of the output to lower a noise floor. In one example, spurious tones can be reduced in a negative voltage generator of a radio frequency (RF) attenuator.

There is a need for an inexpensive, high-performance, fully-integrable, multistandard transceiver, which suppresses spurious noise signals. The invention provides a topology that satisfies this need, providing a first mixer for receiving an input signal x(t), and mixing it with a multi-tonal mixing signal φ1 to generate an output signal φ1 x(t), and providing a second mixer for receiving the φ1 x(t) signal, and mixing it with a mono-tonal mixing signal φ2, to generate an output signal φ1 φ2 x(t). The two mixing signals emulate an LO signal because φ1*φ2 has significant power at the frequency of the LO signal being emulated. The topology also includes a power measurement circuit for measuring the power of the output signal φ1 φ2 x(t). This power output signal is used to vary the characteristics of the mono-tonal mixing signal φ2 to reduce the power level of said output signal.

A system and method for implementing dynamic spur avoidance in a high speed receiver environment is provided. For a plurality of radio frequency (RF) input signal ranges, a range of intermediate frequency (IF) signals and a noise floor for each IF signal is determined. An identification of spurs that will affect the noise floor is also determined from a look up table for each range of the RF inputs. A frequency plan that sets local oscillator and constituent oscillator signals is selected such that the IF signals generated from the RF input will avoid lower order spurious responses of the identified spurs within the IF signal range.

A surface acoustic wave device has high power withstanding performance and is able to effectively suppress an undesirable spurious response. The surface acoustic wave device includes an LiNbO₃ substrate having Euler angles (0°±5°, θ±5°, 0°±10°), an electrode that is disposed on the LiNbO₃ substrate and that has an IDT electrode made mainly from Cu, a first silicon oxide film that is disposed in an area other than an area in which the electrode is disposed to have a thickness equal to that of the electrode, and a second silicon oxide film that is disposed so as to cover the electrode and the first silicon oxide film, wherein the surface acoustic wave device utilizes an SH wave, wherein a duty D of the IDT electrode is less than or equal to about 0.49, and θ of the Euler angles (0°±5°, θ±5°, 0°±10°) is set to fall within a range that satisfies the following inequality:

−10×D+92.5−100×C≦θ≦37.5×D²−57.75×D+104.075+5710×C²−1105.7×C+45.729

D: duty

C: thickness of the IDT electrode normalized using a wavelength λ.

A plurality of surface acoustic wave filters having different center frequencies is provided on a piezoelectric substrate. Either input terminals or output terminals, or both input terminals and output terminals of the surface acoustic wave filters are integrated. Of the surface acoustic wave filters, a surface acoustic wave filter having a higher center frequency is configured so as to suppress a spurious response in the proximity of the high-frequency side in or outside a passband in the filter characteristics of a surface acoustic wave filter having a lower center frequency, for example, such that the width or pitch of electrode fingers in at least one region of reflectors differs from that in other regions.

Methods and systems utilizing seismic sensors configured or designed for use in seismic signal detection are provided so as to reduce the occurrence of spurious responses of the sensors. A method of seismic surveying using a seismic sensor may include the steps of deploying the seismic sensor at a location for seismic signal detection and acquiring seismic signals. The seismic signals may include high frequency response signals containing spurious response signals at an identifiable bandwith. The method may further include applying spurious response cancellation based on the bandwidth location of the spurious response signals and generating modified seismic waveforms having extended frequency bandwidth.

The invention discloses a vapor phase epitaxy device and a vapor phase epitaxy method. The disclosed vapor phase epitaxy device comprises a reaction chamber, a plurality of reaction gas spraying heads arranged in the reaction chamber, a plurality of trays corresponding to the plurality of reaction gas spraying heads, and a power shaft driving the trays, wherein the power shaft comprises revolution shafts and a plurality of rotation shafts, the rotation shafts correspond to the trays one by one; and the trays are respectively connected with the corresponding rotation shafts, or connected with the revolution shafts and the corresponding rotation shafts alternatively. By utilizing the vapor phase epitaxy device and the vapor phase epitaxy method, the flow instability in the chemical vapor phase epitaxy can be reduced effectively, the spurious response times can be decreased, also the problem of the thickness of a quantum well can be solved effectively, different selections can be provided for the growing process of different heterogenous junctions, and the quality of semiconductor elements can be improved.

A longitudinally coupled resonator-type surface acoustic wave filter includes a low acoustic velocity film and a piezoelectric film stacked over a high acoustic velocity component in which a bulk wave propagates at an acoustic velocity higher than an acoustic velocity of an elastic wave that propagates in the piezoelectric film. IDT electrodes are provided on one surface of the piezoelectric film. The longitudinally coupled resonator-type surface acoustic wave filter uses a SH wave. At least one of the IDT electrodes has a duty factor that is adjusted over an entire length of the one of the IDT electrodes in the direction of elastic wave propagation to suppress a Rayleigh wave spurious response.

A surface acoustic wave filter comprised of a plurality of surface acoustic wave resonators having different resonance frequencies, the filter comprising a substrate made of a lithium niobate, comb electrodes (1201 and 1202) formed on the substrate, and a thin dielectric film covering the comb electrodes (1201 and 1202), wherein the surface acoustic wave resonator having a lower resonance frequency is formed to have a metallization ratio larger than a metallization ratio of the surface acoustic wave resonator having a higher resonance frequency, thereby providing the surface acoustic wave filter and an antenna duplexer featuring superior characteristics with insignificant ripples while suppressing spurious responses of the surface acoustic wave resonators.

A surface acoustic wave device has a duty that is greater than about 0.5, attenuation outside the pass band is increased, and an undesirable spurious response is effectively suppressed. The surface acoustic wave device includes an LiNbO₃ substrate having Euler angles (0°±5°, θ±5°, 0°±10°), an electrode that is provided on the LiNbO₃ substrate and that includes an IDT electrode primarily made of Cu, a first silicon oxide film that is provided in an area other than an area in which the electrode is arranged so as to have a thickness substantially equal to that of the electrode, and a second silicon oxide film that is arranged so as to cover the electrode and the first silicon oxide film, wherein the surface acoustic wave device utilizes an SH wave, wherein a duty D of the IDT electrode 3 is at least about 0.52, and θ of the Euler angles (0°±5, θ+5°, 0°±10°) is set so as to fall within a range that satisfies the following Inequality (1A) or (1B):

(1) When 0.52≦D≦0.6, −10×D+92.5−100×C≦θ≦37.5×D²−57.75×D+104.075+5710×C²−1105.7×C+45.729  Inequality (1A)

(2) When D>0.6, 86.5−100×C≦θ≦37.5×D²−57.75×D+104.075+5710×C²−1105.7λC+45.729  Inequality (1B)

• • where D is a duty, and C is a thickness of the IDT.

Provided is a frequency converter that can remove a DC offset and suppress spurious response and intermodulation. The frequency converter receives a reference signal and a local oscillator signal and outputs a frequency component corresponding to the sum or difference of the reference signal and the even-order harmonics of local oscillator signal. The frequency converter includes a reference signal input part including a pair of MOS transistors connected in a differential amplifier form, which have gates to which positive and negative reference signals having a differential phase difference therebetween are respectively input, and first, second, third and fourth frequency conversion parts each of which is connected to the reference signal input part and includes a pair of MOS transistors. Local oscillator signals having a differential phase difference therebetween are input to the gates of the MOS transistors of the first and second frequency conversion parts. Local oscillator signals, which have phases orthogonal to phases of the local oscillator signals input to the first and second frequency conversion parts, are input to the gates of the MOS transistors of the third and fourth frequency conversion parts.

A mobile wireless communication device (10) having a direct conversion receiver (20) reduces spurious mixer response by predicting blockers on the received RF signal. The chopping frequency of the mixer is changed (305) dynamically in response to the prediction of blockers on the input signal to avoid the mixing the blocker with chopper spurs, thereby improving the response of the receiver. In some embodiments, the mixer is disabled momentarily (402) to verify that poor signal quality results from mixing chopper spurs with blockers. In hopping mode applications, the chopper frequency is changed only on channels having a low confidence factor (512).

An acoustic wave resonance device includes: piezoelectric substrate (1), first acoustic wave resonator (100) provided on an upper surface of piezoelectric substrate (1) and including first interdigital transducer electrode (110), and second acoustic wave resonator (200) provided on piezoelectric substrate (1) and including second interdigital transducer electrode (210). First acoustic wave resonator (100) and second acoustic wave resonator (200) are connected to each other. An overlap width of a plurality of first comb-shaped electrodes (112) forming first acoustic wave resonator (100) is larger than an overlap width of a plurality of second comb-shaped electrodes (212) forming second acoustic wave resonator (200). With such a configuration, frequencies in which a transverse mode spurious response is generated can be distributed and loss can be reduced.

A method for correcting feed through signals for use with an oscilloscope employing Digital Bandwidth Interleaving is provided. The method comprises the steps of converting an original signal to a frequency other than an original frequency of the original signal, determining one or more feed through signals not converted with the original signal, providing an offsetting correction signal and combining the converted signal, the non-converted feed through signal, and the offsetting correction signal.

In an elastic wave apparatus, a first dielectric layer is laminated on a piezoelectric substrate. An electrode structure is provided at an interface between the first dielectric layer and the piezoelectric substrate. The electrode structure includes a first electrode structure of an elastic wave filter and a second electrode structure of elastic wave resonators. The elastic wave resonators are electrically connected to the elastic wave filter. An anti-resonant frequency at which the extreme impedance values of the elastic wave resonators are obtained is in a frequency band in which the higher-order mode spurious response of the elastic wave filter appears.

The invention relates to a short-wave full-band broadband multi-channel receiving system. The system comprises a power supply module, a radio frequency signal processing subsystem, a digital signal processing subsystem and a clock circuit, the radio frequency signal processing subsystem comprises an input protection circuit, an antenna attenuation circuit, a low-pass filter, a mode switching circuit, a high/low-pass preselection filter and a full-band high-linearity low-noise amplifier which are connected in sequence. The digital signal processing subsystem comprises two ADC acquisition circuits and a digital signal processing module which are connected in sequence. A radio frequency signal processed by the full-band high-linearity low-noise amplifier is divided into two parts through thepower divider and then input into the two ADC acquisition circuits for sampling processing, the clock circuit is connected with the two ADC acquisition circuits and the digital signal processing module, and the digital signal processing module is connected with an Ethernet transmission module. According to the invention, the problems of insufficient frequency band coverage, insufficient dynamic range, false response and the like of the current short-wave receiving equipment are effectively solved.

A dielectric resonator body for a multi-mode cavity filter, the resonator body including: a piece of first dielectric material, with at least one substantially flat face for mounting on a substrate, the piece of first dielectric material having a shape such that it can support at least a first resonant mode and at least one spurious response; and a layer of conductive material at least partially coating the resonator body; wherein the piece of first dielectric material includes at least one region having a different dielectric constant to the first dielectric material, whereby the presence of the region of different dielectric constant alters the frequency separation of the resonant mode and the spurious response.

An elastic wave filter includes electrode fingers, a first busbar and a second busbar, and inclined electrode portions each having a narrower distance between the electrode fingers from the first busbar toward the second busbar. The elastic wave filter includes a dummy electrode disposed in at least one of the input-side IDT electrode portion and the output-side IDT electrode portion to suppress reflection of a diffracted elastic wave by the busbar and to suppress spurious response at an end portion in a frequency pass-band. The dummy electrode has a width dimension and a pitch that are determined such that none of a period shorter than a shortest period of the electrode fingers and a period longer than a longest period of the electrode fingers is satisfied.